Meta

Congenital cataract is the most common cause of treatable visual impairment

Congenital cataract is the most common cause of treatable visual impairment in children worldwide. congenital cataract causing mutation c.1751C>T in the gene and the previously reported splice mutation c.2826-9G>A in two new TMC353121 families. Additionally, we report a rare variant rs139787163 potentially associated with increased susceptibility to cataract. Thus mutations in account for 4.7% of inherited cataract cases in South-Eastern Australia. Interestingly, the identified rare variant provides a link between congenital and age-related cataract. Introduction Cataract is an opacification of the crystalline lens. Congenital and juvenile cataract form a disease spectrum with presentation from birth or during early childhood and are generally referred to as congenital cataract [1]. Congenital cataract is the leading cause of childhood blindness and accounts for 1C6 and TMC353121 5C15 cases per 10,000 live births respectively, in developed and poor regions of developing countries [2], [3]. Inherited congenital cataract accounts for one quarter of the cases [4]. Its genetic heterogeneity is evidenced by the presence of causative mutations in at least 24 structurally and functionally important genes in the lens, with mutations in ten crystallin genes accounting for 50% of the known mutations [4]. Mutations in the gene have been recently identified to cause congenital cataract [5], [6], [7], [8]. Five different causative mutations with autosomal dominant mode of inheritance have been reported each in an American, Australian, British and Efnb2 two Chinese families [5], [6], [8]. One mutation with autosomal recessive mode of inheritance was reported in a Pakistani family [7]. Age-related cataract, the major cause of blindness in the elderly, is believed to result from both genetic predisposition and environmental factors [9]. Synonymous and non-synonymous variants in the gene have been associated with age-related cataract in multiple populations [5], [10], [11], [12]. Thus has been implicated in both congenital and age-related cataract suggesting a vital role of this gene in lens development and in maintaining lens cell homeostasis and transparency. To date, the overall genetic contribution of the gene to inherited congenital cataract is not known. With this objective, in the present study, we screened a South-Eastern Australian cohort of familial cataract cases for causative mutations in the gene. We report a novel causative missense mutation in the gene in one family and a previously reported splice mutation c.2826-9G>A [6] in two new families. Additionally, we report a rare non-synonymous variant in the gene that may be increasing susceptibility to cataract and, providing a link between congenital and TMC353121 age-related cataract. Materials and Methods Ethics Statement Ethics approval for the study was obtained from the Southern Adelaide Clinical Human Research Ethics Committee, Adelaide, South Australia, the Royal Victorian Eye and Ear Hospital (RVEEH) Human Research Ethics Committee, Melbourne, Victoria, and The University of Sydney and Sydney West Area Human Research Ethics Committees, New South Wales, Australia. All participants gave written informed consent. Where participants were minor or unable to personally provide consent, written informed consent was obtained from the parent, legal guardian or an authorized person. Patient Recruitment This study attempted to recruit all familial congenital and juvenile cataract cases in the last 12 years from three states of South-Eastern Australia, South Australia, Victoria and Tasmania, and thus approximates a population-based approach in this region. Probands with familial cataract and their family members were recruited from the Flinders Medical Centre (Adelaide), Womens and Childrens Hospital (Adelaide), Royal Childrens Hospital (Melbourne) and RVEEH (Melbourne). RVEEH also served as a tertiary referral centre for patient recruitment from Tasmania. Family history of the disease in all the families was available through previous clinical records. Genomic DNA of recruited individuals was extracted from either whole blood or saliva or buccal swab using standard methods. Sequencing TMC353121 Analysis Probands from 84 families were included in this study. All 17 exons of the gene were amplified by PCR and sequenced at the Australian.